Effervescence assisted dispersive liquid-liquid microextraction with extractant removal by magnetic nanoparticles

In this article, effervescence assisted dispersive liquid-liquid microextraction with extractant removal by magnetic nanoparticles is presented for the first time. The extraction technique makes use of a mixture of 1-octanol and bare Fe3O4 magnetic nanoparticles (MNPs) in acetic acid. This mixture is injected into the sample, which is previously fortified with carbonate, and as a consequence of the effervescence reaction, CO2 bubbles are generated making possible the easy dispersion of the extraction solvent. In addition, the MNPs facilitates the recovery of the 1-octanol after the extraction thanks to the interaction between hydroxyl groups present at the surface of the MNPs and the alcohol functional group of the solvent. The extraction mode has been optimized and characterized using the determination of six herbicides in water samples as model analytical problem. The enrichment factors obtained for the analytes were in the range 21-185. These values permit the determination of the target analytes at the low microgram per liter range with good precision (relative standard deviations lower than 11.7%) using gas chromatography (GC) coupled to mass spectrometry (MS) as analytical technique.